Clock



FIG. 1 is a front perspective view of a clock showing our new design;

FIG. 2 is a front elevational view thereof;

FIG. 3. is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a right side elevation thereof; and,

FIG. 6 is a left side elevation thereof.

The broken lines showing portions of the clock in FIGS. 1 and 3 are for illustrative purposes only and do not form part of the claimed design. 

We claim the ornamental design for a clock, as shown and described. 